This is the XS Scuba Propel Fin Adult Open Heel Snorkeling Fins Features: Use with bare feet or lightweight booties Quick and easy adjustable heel straps Much more range of fit than shoe fins Soft thermoplastic rubber heel strap & foot pocket Lightweight and easy for travel Perfect for snorkeling The XS Scuba Propel Fins are made to use on your bare feet or lightweight booties with a quick and easy adjustable heel strap.